True Frogs: Ranidae

The World Conservation Union (IUCN) lists two of the species as being Extinct, which means that they are no longer in existence; twenty species that are Critically Endangered and face an extremely high risk of extinction in the wild; fifty-nine species that are Endangered and face a very high risk of extinction in the wild; eighty-four that are Vulnerable and face a high risk of extinction in the wild; fifty-nine that are Near Threatened and at risk of becoming threatened with extinction in the future; and 132 that are Data Deficient, which means that scientists do not have enough information to make a judgment about extinction threat.

The two Extinct species are the Las Vegas leopard frog, which is also known as the Vegas Valley leopard frog, and another species known only by its scientific name of Nannophrys guentheri. The Las Vegas leopard frog was only found in a few places north of Las Vegas Valley in Nevada, but it has not been seen since 1942. Ecologists believe that it died off when people rerouted water from the frog's breeding areas to the growing city of Las Vegas. A few small areas with enough water still remain, but people introduced bullfrogs to those areas. Since bullfrogs eat other, smaller frogs, any remaining Las Vegas leopard frogs would probably have been gobbled up. No one has seen the other Extinct species, Nannophrys guentheri, since the first one was seen in Sri Lanka more than a century ago.

One of the twenty Critically Endangered true frogs is the dusky gopher frog of the United States, which is also known as the Mississippi gopher frog. Although this species once lived in parts of Louisiana, Mississippi, and Alabama, it now only survives in a small area called Glen's Pond, which is in Mississippi's Desoto National Forest. The last members of this species were seen in Alabama in 1922 and in Louisiana in 1967. In 2001 fewer than one hundred adult frogs were still alive in Glen's Pond. Ecologists mainly blame the drop in numbers on two diseases caused by fungi. One of the fungi, known as chytrid (KIT-rid) fungus, has also killed many other frogs around the world. A Gopher Frog Recovery Team is now watching over the frog and its habitat and is trying to treat the tadpoles infected with the fungus.

In addition to the at-risk true frogs noted above, the U.S. Fish and Wildlife Service also considers four to be Endangered or Threatened. These include the California red-legged frog and the Chiricahua leopard frog, which are Threatened or likely to become endangered in the near future; and the Mississippi gopher frog described above and the mountain yellow-legged frog, which are Endangered or in danger of extinction throughout all or a significant portion of their ranges.